摘要:

SummaryKato, M.: Further comments on an ophioglossoid archetype for the angiosperm carpel: Ovular paedomorphosis. ‐Taxon40: 189–194. 1991. ‐ ISSN 0040‐0262.Kato's recent hypothesis on the origin of the angiosperm carpel, suggesting an ophioglossoid fertile leaf as an archetype for the carpel, is evaluated in the context of heterochrony, which is argued to have been a major factor in the origin of angiosperms. Anatropy of angiosperm ovules, the most primitive type, is interpreted as derived by paedomorphosis from hyponastic curvature of ophioglossoid sporophore primordia and also leaf primordia, concomitant with paedomorphic changes at various levels of floral organization.

ISSN:0040-0262    

DOI:10.2307/1222972

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummarySmith, G. F.&Tiedt, L. R.: A rapid, non‐destructive osmium tetroxide technique for preparing pollen for scanning electron microscopy. ‐Taxon40: 195–200. 1991. ‐ ISSN 0040‐0262.A new, rapid, non‐destructive technique for the preparation of pollen is described, in which dissected anthers are fixed with osmium tetroxide vapour. This method permits the examination without modifying the pollen grain morphology and ultrastructure and the natural state of hydration. Apertural structures are perfectly preserved and neither debris nor artifacts are deposited on the grains. The pollen cementing substances, such as pollenkitt, remain intact and can assist in the functional interpretation of pollen types. This new method may help to obtain optimal structural and functional information from pollen study.

ISSN:0040-0262    

DOI:10.2307/1222973

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryTucker, A. O., Maciarello, M. J.&Tucker, S. S.: A survey of color charts for biological descriptions. ‐Taxon40: 201–214. 1991. ‐ ISSN 0040‐0262.Color charts for biological descriptions have been published since 1776. These have varied in form to include bound volumes and fans with pigment samples or color printing and have been used to describe a range of organisms as specific as one genus to all natural history subjects. We recommend the format of the second edition of the Royal Horticultural Society Colour Chart (c. 1986) in conjunction with the cross‐reference for other color charts from the 1966 edition.

ISSN:0040-0262    

DOI:10.2307/1222974

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryChase, M. W.&Hills, H. H.: Silica gel: An ideal material for field preservation of leaf samples for DNA studies. ‐Taxon40: 215–220. 1991. ‐ ISSN 0040‐0262.Silica gels an inexpensive and reliable substance to preserve field‐collected leaves for molecular studies of variation in DNA. A method for its utilization is explained, and results are presented, comparing total cellular DNA samples extracted from a set of fresh and silica‐gel dried samples of the same species, as well as examining the efficiency of endonuclease restriction and intactness of DNA from of a set of field‐collected leaves preserved with silica gel.

ISSN:0040-0262    

DOI:10.2307/1222975

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryZardini E. M., Peng, C.‐I&Hoch, P. C.: Chromosome numbers inLudwigiasectOligospermumand sect.Oocarpon (Onagraceae). ‐ Taxon40: 221–230. 1991. ‐ ISSN 0040‐0262.Chromosome numbers are reported from all nine species (12 taxa) ofLudwigiasect.Oligospermumandsect. Oocarpon, including three not reported previously:L. hookeri(2n= 32),L. peduncularis(2n= 32), both ofL.sect.Oligospermum, andL. torulosa(2n= 16) of the monotypicL.sect.Oocarpon.An earlier count ofn= 8 forL. hookeriwas based on a mis‐identified specimen ofL. peploides.Counts are also reported for three naturally occurring hybrids. Chromosome counts from a total of 141 strains are included, with full voucher information for each. New data are compared with all previous reports for the species of these sections.

ISSN:0040-0262    

DOI:10.2307/1222976

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryCheek, M.&Rakotozafy, A.: The identity of Leroy's fifth subfamily of theMeliaceae, and a new combination inCommiphora (Burseraceae). ‐ Taxon40: 231–237. 1991. ‐ ISSN 0040‐0262.Neomangenotia ankaranensisLeroy, placed by that author in a monotypic subfamily of theMeliaceaeon the basis of a single collection made by him from northern Madagascar, has recently been recollected and found to be congeneric with the large, widespread and mainly palaeotropical genusCommiphora (Burseraceae).

ISSN:0040-0262    

DOI:10.2307/1222977

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryBaatout, H.; Marrakchi, M.&Combes, D.: Genetic divergence and allozyme variation within and among populations ofHedysarum spinosissimumsubsp.capitatumand subsp.spinosissimum (Papilionaceae). ‐ Taxon40: 239–252. 1991. ‐ ISSN 0040‐0262.Three outcrossing populations ofHedysarum spinosissimumsubsp.capitatumand two self‐pollinating populations ofH. spinosissimumsubsp.spinosissimumwere surveyed for variation at 36 allozyme loci. The proportion of polymorphic loci ranged from 25.0 to 75.0 % in subsp.capitatumand from 27.8 to 30.6 % in subsp.spinosissimum, and the mean heterozygosity from 0.088 to 0.299 in subsp.capitatumand from 0.086 to 0.097 in subsp.spinosissimum.No karyotypic differences distinguish the two subspecies, and no hybridization between the allogamousH. spinosissimumsubsp.capitatumand the autogamous subsp.spinosissimumwas noted. Allele frequency differences between the two subspecies indicate that they are clearly distinct in several genes coding for the enzymes peroxidase, esterase and acid phosphatase. The level of genetic divergence at the enzyme level, revealed by electrophoretic analysis of the two taxa, supports their specific distinctness, the mean genetic distance between them being 0.45 ‐ which is indicative of a long period of lack of gene flow between them.

ISSN:0040-0262    

DOI:10.2307/1222978

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryLinder, H. P.: Confidence limits in phylogenies: An example from the AfricanRestionaceae. ‐ Taxon40: 253–266. 1991. ‐ ISSN 0040‐0262.The four ways of assessing the confidence limits in the nodes of a cladogram (character homologies, character numbers per node, bootstrap percentiles and the monophyly index) are reviewed. The methods are applied to a cladogram of the genera of the AfricanRestionaceae, and the confidence limits of each node are discussed. It is shown that there is a great variation in the confidence limits of the various nodes. By combining the various methods it is possible to assess which nodes are not likely to change with the addition of new data, and which may change in the future. It is suggested that this method be employed in making decisions about the establishment of formal classifications, thus avoiding unnecessary changes in the formal taxonomy when further data result in small changes in the cladogram topologies.

ISSN:0040-0262    

DOI:10.2307/1222979

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryTadesse, M.: Dr. Herbert F. Mooney, founder of the National Herbarium of Ethiopia (ETH). ‐Taxon40: 267–272. 1991. ‐ ISSN 0040‐0262.The life and achievements of Dr. Herbert F. Mooney are outlined, principally in regard to his involvement with the foundation of the National Herbarium of Ethiopia. Unpublished correspondence of Dr. Mooney with various Kew botanists documents his unique contribution to the early stages of that herbarium.

ISSN:0040-0262    

DOI:10.2307/1222980

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryOdell, E. A.&Vander Kloet, S. P.: The utility of stem characters in the classification ofVacciniumL.(Ericaceae). ‐ Taxon40: 273–283. 1991. ‐ ISSN 0040‐0262.The efficacy of 28 stem features at re‐creating the classification of 13 established sections ofVacciniumwas tested using taximetric analysis and was found to be wanting. However, adding three reproductive features to the matrix was sufficient to recover all of these sections. Stem characters will, therefore, recover specific groups previously circumscribed by a suite of both reproductive and vegetative features.

ISSN:0040-0262    

DOI:10.2307/1222981

出版商:Wiley    

年代:2019

数据来源: WILEY